#include "stdio_impl.h"
#include "intscan.h"
#include "shgetc.h"
#include <inttypes.h>
#include <limits.h>
#include <wctype.h>
#include <wchar.h>

/* This read function heavily cheats. It knows:
 *  (1) len will always be 1
 *  (2) non-ascii characters don't matter */

static size_t do_read(FILE *f, unsigned char *buf, size_t len)
{
    size_t i;
    const wchar_t *wcs = f->cookie;

    if (!wcs[0]) wcs=L"@";
    for (i=0; i<f->buf_size && wcs[i]; i++)
        f->buf[i] = wcs[i] < 128 ? wcs[i] : '@';
    f->rpos = f->buf;
    f->rend = f->buf + i;
    f->cookie = (void *)(wcs+i);

    if (i && len) {
        *buf = *f->rpos++;
        return 1;
    }
    return 0;
}

static unsigned long long wcstox(const wchar_t *s, wchar_t **p, int base, unsigned long long lim)
{
    wchar_t *t = (wchar_t *)s;
    unsigned char buf[64];
    FILE f = {0};
    f.flags = 0;
    f.rpos = f.rend = f.buf = buf + 4;
    f.buf_size = sizeof buf - 4;
#ifndef OS_OPTION_NUTTX_VFS
    f.lock = -1;
#endif
    f.read = do_read;
    while (iswspace(*t)) t++;
    f.cookie = (void *)t;
    shlim(&f, 0);
    unsigned long long y = __intscan(&f, base, 1, lim);
    if (p) {
        size_t cnt = shcnt(&f);
        *p = cnt ? t + cnt : (wchar_t *)s;
    }
    return y;
}

unsigned long long wcstoull(const wchar_t *restrict s, wchar_t **restrict p, int base)
{
    return wcstox(s, p, base, ULLONG_MAX);
}

long long wcstoll(const wchar_t *restrict s, wchar_t **restrict p, int base)
{
    return wcstox(s, p, base, LLONG_MIN);
}

unsigned long wcstoul(const wchar_t *restrict s, wchar_t **restrict p, int base)
{
    return wcstox(s, p, base, ULONG_MAX);
}

long wcstol(const wchar_t *restrict s, wchar_t **restrict p, int base)
{
    return wcstox(s, p, base, 0UL+LONG_MIN);
}

intmax_t wcstoimax(const wchar_t *restrict s, wchar_t **restrict p, int base)
{
    return wcstoll(s, p, base);
}

uintmax_t wcstoumax(const wchar_t *restrict s, wchar_t **restrict p, int base)
{
    return wcstoull(s, p, base);
}
